System for Distributing DC Power to and Controlling Building Devices

ABSTRACT

A scalable DC power distribution and control system suitable for commercial buildings includes one or more power and control hubs. Each DC power and control power hub provides power and control for any suitable distributed DC loads such as light-fixtures. AC power from the electric utility is applied to the power and control hub and is converted to DC power for distribution to DC loads within the space using low-voltage cables.

RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/201,926, filed Nov. 27, 2018, which is a continuation of U.S.application Ser. No. 15/166,078, filed May 26, 2016, now U.S. Pat. No.10,141,739, which in turn claims priority to U.S. ProvisionalApplication 62/166,512 filed May 26, 2015.

FIELD

The inventions described below relate to the field of powering andcontrolling devices located in building spaces.

BACKGROUND

Building power systems typically distribute alternating-current (AC)electrical power that is delivered by an electric utility. Someelectrical devices inside the building are design to operate based uponAC electrical power, for example incandescent light fixtures. Manyelectrical devices within a building require direct-current (DC)electrical power to operate. A typical example is a lamp constructedusing light emitting diodes (LEDs). Because most building power systemsdistribute AC power, devices requiring DC power typically are associatedwith a device-specific AC/DC converter. AC/DC converters, however,generate power losses and using a dedicated AC/DC converter for eachdevice that runs on DC power multiplies the power loss. Additionally,when the power distribution within a building is AC, the power wiresmust generally be housed in conduits and raceways as a safety measureincreasing complexity and expense as well as potentially detracting fromroom aesthetics.

SUMMARY

The devices and methods described below provide for a scalable DC powerdistribution and control system suitable for commercial buildings. A DCpower and control power hub provides power and control for any suitabledistributed DC loads such as light-fixtures. AC power from the electricutility is applied to the power and control hub and is converted to DCpower for distribution to DC loads within the space using low-voltagecables. Thus, the power loss due to many different and inefficient AC/DCconverters can be consolidated into a single, more efficient conversionto save energy and conduits and raceways can be omitted.

Low-voltage cables are also used to transmit data signals. The devicesand methods described below provide an opportunity to both power andcontrol a device with a single cable more efficiently than existingapproaches such as Power over Ethernet (POE).

A system for controlling and distributing DC power includes a power hubhaving a hub controller, a power converter converting AC power to DCpower, one or more variable voltage regulators operatively connected tothe power converter and controlled by the hub controller, or more outputports, each of the one or more output ports operatively connected toeach of the one or more variable voltage regulators for providingregulated DC power and for receiving and transmitting data and controlsignals to one or more primary loads, one or more communicationinterfaces operatively connected to the hub controller for transmittingand receiving data and control signals over a network. Connected to thepower hub are one or more primary loads, each primary load operativelyconnected to one of the one or more output ports, each primary loadhaving a load control module, the load control module having a loadcontroller operatively connected to the hub controller for receiving andtransmitting data and control signals to the hub controller, a pluralityof output ports operatively connected to the load controller, theplurality of output ports providing DC power to secondary loads andtransmitting and receiving data and control signals to and from the loadcontroller and a load driver for distributing DC power to the primaryload, the load driver operatively connected to and under control of theload controller.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a power-distribution and control system.

FIG. 2 is a schematic representation of the power-distribution andcontrol system shown in FIG. 1.

FIG. 3 is a schematic representation of a load control module in thepower-distribution and control system shown in FIG. 1.

FIGS. 4A and 4B are schematic representations of the conductors insidethe cables connecting components in the power distribution and controlsystem of FIG. 1.

FIG. 5 is an exemplary building floor plan that depicts how thepower-distribution and control system shown in FIG. 1 is connected tothe AC power-distribution system running through the building.

FIG. 6 is a perspective view of another power-distribution and controlsystem.

DETAILED DESCRIPTION OF THE INVENTIONS

FIG. 1 shows a perspective view of power-distribution and control system100. The power-distribution and control system includes one or morepower distribution hubs such as hub 102. Power distribution hubs such ashub 102 may be located in any suitable location such as on a ceiling, ina ceiling plenum, under a raised floor, on a wall, in a rack orenclosure mounted, or placed in a distribution closet for electrical ortelecom equipment. Hub 102 is connected to AC power wires that areconnected to the building AC power distribution system. An LED lightfixture 104 is connected to the hub 102 through cable 106. As describedin more detail below, cable 106 transmits both power and control signalsfrom hub 102 to any suitable distributed DC loads such as light fixture104. An LED light fixture 108 is connected to light fixture 104 throughanother cable 110. Cable 110 has the same construction as cable 104 butmay differ in its length. An LED light fixture 112 is connected to lightfixture 108 through cable 114. Cable 114 has the same construction ascables 106 and 110 but may differ in its lengths. The structure ofcables 106, 110 and 114 is described in more detail below with referenceto FIGS. 4A and 4B. Additional light fixtures or other DC loads can beadded in a daisy-chain configuration with cables having the sameconstruction as cables 106, 110, and 114. Distributed DC loads may besensors, sound masking components, sub-metering components, emergencylighting components and occupancy density mapping components.Additionally, one or more additional light fixtures can be connecteddirectly to hub 102 and additional light fixtures can be daisy-chainedto the additional light fixtures that are directly connected to the hubusing additional cables having the same construction as cables 106, 110,and 114. While the system 100 is shown and described as powering andcontrolling LED light fixtures, it should be understood that a systemaccording to the present disclosure can control and power other types oflight fixtures as well, for example, fluorescent light fixtures.Additionally, while system 100 is shown and described with one hub 102,it should be understood that a system according to the presentdisclosure can include multiple interconnected hubs that can communicatethrough each other through a building computer network.

FIG. 2 shows a schematic representation of the power-distribution andcontrol system shown in FIG. 1. Hub 102 includes an AC/DC converter 116that converts the AC power from the AC power wires 99 that are connectedto Hub 102 into DC power that is used by the power-consuming devices inthe system. Hub 102 also contains voltage regulators 118 that regulatethe output voltage of the AC/DC converter. One voltage regulator stageper output connection is utilized to guarantee that amperage levelsprovided stay within safety NEC limits for Class 2 power. Voltageregulators 118 may be individual per port or combined on a commonbackplane or splitter board. Additionally each regulator stage utilizescurrent limiting to protect from both over current and short circuitevents in a manner that does not damage the electrical components of hub102 or any attached light fixtures or control devices.

Hub 102 also contains a controller 120 containing a memory 122 and oneor more microprocessors such as microprocessor 124 and communicationtransceiver 123. The controller 120 controls the AC/DC converter 116 andthe voltage regulators 118, and can also be used to control the entiresystem 100. Controller 120 administrates communication between lightfixtures or control accessory devices connected physically or logicallyto hub 102 through communication transceiver 123 and output ports 126,128, 130 and 132. Controller 120 also administrates wired and wirelesscommunication with one or more network computers, other hubs and withworkstations and mobile devices through communication transceiver 123using wired network interface 136 and a wireless network interface 138respectively. Having both wired and wireless communications capabilitiesenables the hubs and loads to determine which devices are physicallyclose together as loads and controllers hard wired together aregenerally within 30-50 feet of each other and would be most likely toneed to participate with the controller in application binding.

Controller 120 manages the list of control bindings that relate controlaccessory inputs to actuator events they assert including, but notlimited to causing lights to turn on, off, or dim, and enabling ordisabling other control accessory devices or subordinate systems such assound masking or emergency signage. Communication addressing and messagerouting are able to work between a set of accessories, light fixtures,and other hub 102 functions without the requirement for a global orsupervisory controller. Hub 102 also includes output ports 126, 128,130, and 132 for distributing the DC power output by the AC/DCconverter. Each output port can provide, for example, 100 W of power andClass II circuits currently allow up to 60 VDC. The output ports can beprogrammed to provide voltages from 12-60 VDC and each output port canoutput power at different voltage levels. For example, output port 126and 128 can output 24V and ports 130 and 132 can output 48V. For ease ofreference, four output ports are shown, but it should be understood thathub 102 can have more or less than four output ports. Hub 102 can alsoinclude one or more connections 134 for providing power and contentsignals such as power and content signal 135 to audio speakers as wellas sending power and control signals 135 and receiving control signalsand data 137 from secondary loads such as sensors or other suitableinfrastructure components.

Hub 102 also includes a wired network interface 136 and a wirelessnetwork interface 138. Interfaces 136 and 138 can be used to connect hub102 to a computer network 140. Network 140 can be a local area network(LAN) that utilizes the IEEE 802.11 or 802.3 standards family variantsor a local control accessory device network utilizing IEEE 802.15.4family technologies, sub Ghz RF, or BlueTooth variants including but notlimited to Bluetooth Smart, BlueTooth Low Energy (BLE), and BlueToothclassic. Alternatively, the computer network 140 can be a wide-areanetwork (WAN) such as the Internet. Through the computer network, hub102 can communicate with other hubs or with a personal computer 142 ormobile device 144 running application software that performs one or moreof the following functions: system configuration and management;real-time graphical display of system data (commonly referred to as“dashboarding”); data analytics; reporting; machine learning of thetypical control functions of other hubs nearby to hub 102 for thepurposes of real-time adaptive self programming of control operationalsequences.

As shown in FIG. 2, each LED fixture 104, 108, 112 respectively includesa load control module 146, 148, 150. One end on each of cables 106, 110,114 plugs directly into an input port on the respective one of loadcontrol modules 146, 148, 150 to connect the fixtures to the system. Theopposite end of cable 106 also plugs directly into output port 126 ofhub 102, the opposite end of cable 110 plugs directly into an outputport of control module 146 and the opposite end of cable 114 also plugsdirectly into an output port of control module 148.

FIG. 3 shows a schematic representation of the load control module 146shown in FIG. 2. Load control modules 148, 150 have the same orsubstantially the same construction as load control module 146. Loadcontrol module 146 includes an input port 152 for receiving a cable (inthis case, cable 106). Load control module 146 receives DC power 143 andcontrol signals 149 through input port 152 and also sends informationmonitoring signals 147A, sensor data 161 and processed sensor data 161Pout from input port 152. Load control module 146 uses all or a subset ofoutput ports to apply DC power 145 to any suitable secondary loads thatare operatively connected to the fixture such as LED lights, occupancysensors, environmental sensors, speakers, IT equipment, personalcomputers, charging receptacles (USB and wireless charging), displays,and potentially any DC load that is 60 VDC and below and draws less than100 W. Load control module also includes an output port 154 forreceiving a cable (in this case cable 110). Load control module servesas a conduit for transmitting DC power to one or more downstream devices(if such downstream devices are connected) through output port 154. Loadcontrol module also serves as a conduit for transmitting control signals149 to the downstream devices and receiving monitoring informationsignals 147B from the downstream devices through output port 154.

Load control module 146 also includes one or more output ports forsecondary loads such as speaker ports 156, 158 and sensor ports 160,162. Each output port for secondary loads is for receiving a cablehaving the construction of cables 106, 110, 114 that is connected on itsopposite ends to a secondary load such as a speaker, for example, aspeaker that is used for sound-masking purposes in an officeenvironment. Alternatively, output ports for secondary loads may beconfigured to use category 5 or category 6 cables to connect secondaryloads such as speakers and sensors that have low current demands. Inthis way secondary loads such as speakers can be powered and controlledthrough the overall control system 100. Each sensor port is forreceiving any suitable cable having the construction similar to cables106, 110, 114 that is connected on its opposite ends to any suitablesecondary load such as a sensor, for example, an occupancy, vacancy,daylight, or temperature sensor. In this way room monitoring sensors canbe powered and controlled through the overall control system 100, andsensor data 161 from the sensor can be processed, used, or reportedexternally by the control system 100.

Load control module 146 further includes one or more primary loadcontrol drivers such as LED driver 164. Primary load control driver 164regulates the DC voltage that is output to the primary load such as theLEDs in the light fixture and protects against voltage fluctuations,which can impact the light output by the LEDs. The LED driver provides aconstant current output typically (but not necessarily) within the rangeof 20 mA to 750 mA and at a voltage range typically (but notnecessarily) 12 VDC-60 VDC. The output of the LED driver powers one ormore LED arrays at a certain level of illumination. The output of theLED driver is tailored to the specific arrangement of LED arrays and thedesired illumination level.

Load control modules such as modules 146, 148 and 150 may include theprimary load control drivers such as LED driver 164 as integratedcomponents as illustrated or the load control drivers may be separatemodular components that can be closely coupled or connected via a wireharness or any suitable bus interface that supports power & data such asa USB interface. The use of separate drivers permits pairing a loadcontrol module with a wider variety of dc/dc driver products that areeither for LED arrays or powering other suitable loads.

Load control module 146 also includes a controller 166 having a memory168 and one or more programmable microprocessors such as microprocessor170. The controller 166 receives and processes control signals throughinput port 152 and controls the LED driver 164, any connected speaker,and any connected sensors accordingly. Additionally, controller 166receives sensor data such as sensor data 161 from any sensors connectedto the load control module and can process that data as desired or canforward processed sensor data 161P to another device on the system. Thecontroller 166 utilizes a hardware unique MAC address to indicate itsmodel number, role, functionality, and logical hierarchy for digitalcommunications within system 100. Controller 166 is addressed withinsystem 100 through its MAC address. Controller 166 can control thecurrent and voltage output by LED driver 164 to change the brightness ofthe LEDs. This regulation can be based upon control signals received bythe controller 166 that have been transmitted through system 100.Illumination levels throughout the driver's full dynamic brightnessrange are commanded through means including 0-10V analog signals ordirect digital communication to controller 166 or by methods such asuniversal asynchronous receiver/transmitter (UART), Serial PeripheralInterface (SPI), Inter-Integrated Circuit (I2C), Digital AddressableLighting Interface (DALI), or Digital Multiplex (DMX) protocols.

FIGS. 4A and 4B schematically depict two different wire configurationsfor the cables used in system 100, such as cables 106, 110, 114. Unlikesystems that use established standards, such as POE, for transmittingpower and data over a single cable, system 100 does not use cables thatare widely used for data transmission, such as Category 5 or 6 cable.The Institute of Electrical and Electronics Engineers (IEEE) type 2 POEstandard limits the current in Category 5 cables to 600 ma per pair witha maximum power available of 25.5 watts. Thus, POE is incapable ofproviding the DC power available from system 100. The use of largerdiameter conductors limit power loss in the cables of system 100 andthus permits daisy-chained configurations. The resistance of the wiresin Cat 5 or 6 cable lead to unacceptable power losses in such aconfiguration.

FIG. 4A shows a three-wire configuration. First wire 172 is a positivepower wire. Second wire 174 is a negative power wire. Third wire 176conducts bidirectional communication of control signals andsystem-management data such as control signals 149, informationmonitoring signals 147A, sensor data 161 and processed sensor data 161P.A fourth wire providing a ground for the communication and controlchannel is not required. Second wire 174 acts as a common ground forboth the power circuit and the communication and control circuit.Preferably, wires 172-76 have a gauge of AWG 18 (wire diameter of 0.0403in.) or larger. In comparison, Cat 5 and Cat 6 cables have wirediameters of 0.02503 in. and smaller.

FIG. 4B shows a four-wire configuration. In this configuration thecontrol signals are delivered on wire 176 and the system management datais delivered on additional wire 178. Wires 453 and 454 (as well as wire451) share wire 452 as a ground wire. Cables providing three or four AWG18 wires can currently be purchased in bulk from a number of sources. Aninstaller can then simply determine the amount of cable needed toconnect two devices, cut out that length of cable, and then addconnectors to the end of the cable on-site. The process of addingconnectors to the end of a cable is known as “terminating” the cable.The use of field-terminable bulk cable in system 100 makes it possibleto place devices in system 100 arbitrarily far apart from each other.The installer can simply cut out the length of bulk cable required tospan the distance and then field-terminate that cable preventing orlimiting service loops which can create power and communication-strengthlosses as well as have a negative effect on aesthetics.

FIG. 5 shows a schematic layout for a space 500. Space 500 may be abuilding, a floor of a building or a portion of a floor of a building.In FIG. 5, space 500 is shown as an entire floor of a building. Aprimary AC power pathway 502 traverses the floor. Secondary AC powerpathways 504 connect hubs 102 to the primary AC power pathway. Forexample, one hub could be installed for every 2,500 square feet ofspace.

FIG. 6 shows a perspective view of another power-distribution andcontrol system 600. This system is similar to system 100 shown in FIG.1, except that the hub 602 is mounted above the ceiling instead of belowthe ceiling so that hub 602 can be hidden from view. Hub 602 isdimensioned so that it can be inserted into the ceiling through thespace taken up by a standard ceiling tile 601 for a commercial space. Inthis manner, hub 602 can be inserted into the ceiling from within theroom by first removing the ceiling tile 601 at the appropriateinstallation location. Once the hub is installed in the ceiling, theceiling tile can be replaced to hide the hub from view. The cableconnecting hub 602 to fixture 604 can also be hidden by routing itthrough the mounting structure for fixture 604.

The disclosed power-distribution and control systems can route DC power,control signals, and sensor data among controllers regardless of howthey are connected. The system is not topology-specific; it is topologyagnostic. Devices such as light fixtures do not need to be connecteddirectly to the hub. They can, instead, be daisy-chained together solong as combined they do not draw more power than a particular huboutput channel can provide. For example, if a hub output can provide 100W, then four devices each drawing 25 W can be connected to that outputin a series fashion. Adding a fifth device that normally draws 25 W,would overload the output unless the devices contain circuitry orsoftware that permits them to reduce their power draw (resulting in lessbrightness, for example, for a light) or coordinate the timing of theirloads to keep the peak below the output channel rating upon thedetection of an overload condition.

Additionally, hubs in power distribution and control system 100 such ashub 102 can communicate with any controller in the system even if it isnot directly connected to them. Packets such as packets 119A and 119Bare addressed to the MAC addresses of particular controllers, andintermediate controllers along the path from the source to destinationdo not serve as a barrier to successful transmission. In this sense thecommunication channel logically acts as a single communication wire,even though it may be physically made up of several wires through thedaisy-chain connections. The controllers use transceivers such astransceiver 123 that can monitor incoming data for packets such aspackets 119A or 119B addressed to them. The communications protocol forsystem 100 uses first-come first-serve priority and employs random-timesfor attempted retransmission when two load control modules send a packetat the same time such that there is a collision. The controllers canself-organize and establish hierarchies according to the principles setforth in U.S. Pat. No. 8,487,474 titled Method and Apparatus forElectrical Load Control Network, which patent is hereby incorporated byreference in its entirety.

While the preferred embodiments of the devices and methods have beendescribed in reference to the environment in which they were developed,they are merely illustrative of the principles of the inventions. Theelements of the various embodiments may be incorporated into each of theother species to obtain the benefits of those elements in combinationwith such other species, and the various beneficial features may beemployed in embodiments alone or in combination with each other. Otherembodiments and configurations may be devised without departing from thespirit of the inventions and the scope of the appended claims.

We claim:
 1. A method of controlling and distributing DC powercomprising the steps of: providing a plurality of power hubs whereineach power hub comprises: a hub controller; a power converter adapted toconvert AC power to DC power; and one or more variable voltageregulators operatively connected to the power converter and controlledby the hub controller; operating the one or more variable voltageregulators to provide regulated DC power to one or more primary loadsand to receive and transmit data and control signals from and to the oneor more primary loads; providing one or more communication interfaces tooperably connect the hub controller to transmit and receive data andcontrol signals; providing each primary load with a load control module,each load control module comprising: a load controller operativelyconnected to the hub controller to receive and transmit data and controlsignals to the hub controller; and a plurality of output portsoperatively connected to the load controller; providing DC power tosecondary loads and transmitting and receiving data and control signalsto and from the load controller; and distributing DC power from the loaddriver to the secondary loads, the load driver operatively connected toand under control of the load controller.
 2. The method of claim 1further comprising the step of operably connecting the plurality ofpower hubs and load controllers to each other via a network.
 3. Themethod of claim 2 further comprising the step of providing the networkwith an exclusive connection to the plurality of power hubs.